#include <bits/stdc++.h>
using namespace std;
int duck[100001];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    int d;
    cin >> d;
    duck[d] = 1;
  }
  int res = 0;
  for (int d = 1; d <= 10000; d++) {
    res += duck[d];
  }
  cout << res;

  return 0;
}